Recent work in this laboratory has demonstrated color-specific features of interconnections between cones and horizontal cells in goldfish retina. We have shown that there are five kinds of cones: long single, short single, and miniature single; long member of double, and short member of double. We have determined the spectral absorption ranges for three of these: short single (blue), short double (green), and long double (red). Using these identifications we have examined the color-coding of inputs to horizontal cells. One type of horizontal cell ("H1") contacts, red-, green-, and blue-, another ("H2") contacts green- and blue-, and a third ("H3") contacts only blue-sensitive cones. All three have axons which end in the inner nuclear layer. We are now attempting to relate these facts to the chromatic organization of horizontal cells as revealed by electrophysiological studies. We shall record from horizontal cells with micropipettes and inject dyes for morphological identification. We shall record intracellularly from cones, seeking evidence of feedback from horizontal cells. We shall reconstruct the synaptic regions of horizontal cell dendrites and axons from serial electron micrographs. We shall begin an analysis of bipolar cells and their synaptic relationships to cones and horizontal cells.